The purpose of this study is to examine precisely how the pathology of basal ganglion disorders relates to abnormal functioning of central dopamine neurons. Initial observations made during this study suggest that the urinary excretion of free dopamine correlates nagatively with the severity of rigidity and akinesa in 27 parkinsonia patients. Free urinary dopamine also correlates with the schizophrenic scale of the MinnesotaMultiphasic Personality Inventory (MMPT). The correlations will be extended to include a total of 50 patients. The study will be expanded by determining whether similar correlations can be found in schizophrenic patients who develop parkinsonism upon treatment with phenothiazines. Further efforts will be made to determine if urinary dopamine in parkinsonian patients who have been treated with levodopa correlates with the degree of neurologic improvement of the degree of mental side effects. We have previously shown that large doses of levodopa suppress conjugation of dopamine. It might be expected that the greater amounts of free dopamine would be associated with greater therapeutic and side effects during levodopa therapy. This effect on conjugation varies considerably between ptients and efforts will be made to correlate the degree of improvement and the extent of the side effects of levodopa with the degree of conjugation of dopa and its metabolities. This clinical study is coupled with several animal studies which are designed to examine factors which regulate the function of dopamine containing neurons in the basal ganglion.